A person with sleep apnoea stops breathing in their sleep. There are three types of sleep apnoea: obstructive, central and complex. The most common of these is obstructive sleep apnoea (OSA).
What is Sleep Apnoea?
Sleep apnoea is a sleeping disorder that causes breathing to be interrupted during sleep. Most people may experience symptoms such as loud snoring, excess fatigue and headaches. Sleep apnoea can be diagnosed following a sleep study or an at-home sleep apnoea test. There are different treatments available which can help to reduce symptoms and the risk of other health conditions. Usually, sleep apnoea can be treated by making lifestyle changes like quitting smoking, reducing alcohol consumption and losing weight.
The three types of sleep apnoea this article will cover are obstructive sleep apnoea (OSA), central sleep apnoea (CSA) and complex sleep apnoea (CompSA).
What is obstructive sleep apnoea?
Obstructive sleep apnoea (OSA) is a sleep-related respiratory condition which causes temporary breathing problems because of the narrowing and blocking of the airways during sleep. The muscles in the throat relax excessively during sleep, thus leading to breathing difficulties. The individual airways become constricted during sleep, restricting air to pass normally. This can result in decreased oxygen levels and increased carbon dioxide in the blood.
When breathing impairments occur, the brain detects this and awakens the individual from sleep to reopen the airways.
Symptoms of OSA include:
- Loud Snoring
- Morning headaches
- High blood pressure
- Decreased interest in sex
- Insomnia: is when you regularly have difficulty falling asleep
- Daytime fatigue
- Mood changes such as depression
Risk factors for OSA:
While obstructive sleep apnoea can affect anyone, certain risk factors increase the likelihood of developing this condition. These risk factors include:
- Obesity: is a major risk factor for sleep apnoea. Excess fat around the neck and constrict the airways. Obesity is believed to predispose to OSA because of mass loading in the upper airway.
- Gender: OSA is more common in men than women.
- Age: sleep apnoea is more common in older adults.
- Smoking: smokers are at higher risk because smoking increases inflammation and fluid retention in the airways.
OSA is the most common type of apnoea and is estimated to affect 1.5 million adults in the UK, with up to 85% being undiagnosed or untreated. OSA, when left untreated, deprives people of sleep and can lead to serious health consequences, including severe daytime sleepiness.
A 2015 review of 11 studies found OSA, on average, was prevalent in 22% of males and 17% of females.
OSA is a serious medication condition and can cause complications if left untreated for example:
- Daytime fatigue
- High blood pressure/heart problems
- Type 2 diabetes
- Liver problems
Diagnostics for OSA include:
- Polysomnography: during a sleep study, you are connected to monitoring equipment. It tracks your lung, heart and brain activity, breathing, and body movements.
- Home sleep apnoea testing: is an at-home version of polysomnography used to diagnose OSA. Such kits focus on detecting breathing pausing during sleep. Though limited in terms of how much information can be acquired, it is still a useful measure.
What is Central Sleep Apnoea?
Central sleep apnoea (CSA) is a sleep disorder characterised by an interruption in breathing. These disruptions are due to the brain’s failure to send appropriate signals to the muscles responsible for regulating breathing.
The brainstem links the brain to the spinal cord and plays a vital role in controlling many important bodily functions, such as breathing and heart rate.
It is important to acknowledge that central sleep apnoea differs from obstructive sleep apnoea, where abnormal breathing results from a blockage in the upper airway.
Some people have no symptoms, but others may notice:
- Mood changes
- Daytime sleepiness
- Abrupt awakening
- Morning headaches
- Difficulty concentrating
- Insomnia
- Waking up with sudden shortness of breath
Some potential causes of CSA:
- Heart failure
- Stroke
- Kidney failure
- Neurological diseases such as Parkinson’s disease and Alzheimer’s disease
- Drugs such as opioids
However, central sleep apnoea can sometimes be idiopathic – meaning that doctors cannot identify an underlying disease.
CSA can occur in a pattern called Cheyne-Stokes breathing, a form of periodic breathing that causes a person to alternate between hyperventilating and not breathing at all. Such type of CSA can occur with congestive heart failure.
Risk factors for CSA:
While central sleep apnoea can affect anyone, certain risk factors increase the likelihood of developing this condition. CSA is more common among older people, with men at a higher risk of OSA and CSA.
CSA is a serious medication condition and can cause complications if left untreated for example:
- Fatigue
- Cardiovascular problems
Treatments for CSA include:
It is important to address the underlying cause of CSA since this may help resolve sleep apnoea. However, this will not always cure the condition. Possible treatments include:
- Addressing associated medical problems: treating those underlying conditions will help your central sleep apnoea. For instance, having therapy for heart failure makes you less likely to develop CSA.
- Reduction of opioid medicines: if opioids cause CSA, healthcare professionals will look to reduce your dose over time.
- Supplemental oxygen: while sleeping may help if you have CSA.
- Continuous positive airway pressure (CPAP): involves a patient wearing a mask over the nose or the nose and mouth during sleep. The mask is connected to pressurised air, which keeps your airways open. It is also a method used to treat OSA.
- Medicines: such as acetazolamide, which is used to stimulate breathing for people with CSA. Such medication is prescribed to help with breathing as an alternative if you cannot tolerate positive airway pressure.
What is Complex Sleep Apnoea?
Complex sleep apnoea (CompSA) is a combination of OSA and CSA. Patients with this type of sleep apnoea may first experience OSA. Patients with CompSA experience persistent breathing problems even after treating the airway obstruction. This usually indicates another underlying factor besides the collapsing of throat muscles contributing to the apnoea.
Symptoms of CompSA are similar to OSA:
- Insomnia: is when you regularly have difficulty falling asleep
- Daytime fatigue
- Headaches
- Confusion about getting up
A 2006 retrospective review of 233 people with sleep apnoea symptoms showed that 15% had complex sleep apnoea, 84% obstructive sleep apnoea and 0.4% had central sleep apnoea. In the study, the researchers could not identify factors that increase the risk for complex sleep apnoea and exact treatments were not identified in this study. Additional research is needed for this sleep apnoea to define the condition better and for more effective treatments to be discovered for patients with this type of apnoea.
However, treatments for CompSA may involve a combination of different interventions, such as treatment for an underlying condition and using CPAP or other positive airway pressure modes.
Ways to improve sleep apnoea
- Eating healthy: Try to eat a balanced diet where possible – one rich in fibre, vitamins, fresh fruits, veg, whole grains and low-fat proteins. Avoid foods with added sugars. Healthier eating habits can also lead to weight loss, which may improve conditions such as obstructive sleep apnoea.
- Exercise during the day: Adding physical activity during the daytime or eating a balanced diet can help you sleep better. Avoid doing any strenuous exercises 3 hours before sleep.
- Sleeping on your side rather than your back
- Using nasal spray to keep air flowing
Worried you may have sleep apnoea?
There are various types of sleep apnoea, and it can often go unnoticed until it is too late. If left untreated, sleep apnoea can cause serious harm to your physical and mental well-being. If you suspect that you may have sleep apnoea, please visit your GP or specialist doctor as soon as possible to begin appropriate investigations and to take charge of your health.
As a leading sleep and respiratory physician specialising in sleep apnoea and sleep-related breathing disorders, I offer consultations to diagnose and treat these conditions. Please contact me if you have any further queries about sleep apnoea or want further advice on the potential treatments available.
